The present invention relates to a furnace, for heating and ultimately melting a material at high temperatures. More particularly, the present invention relates to an easy to use and portable electric furnace having handles to permit the furnace to be vertically lifted and moved about. The furnace is lifted from the base once the metallic material has been melted thereby reducing unnecessary handling of the melted metallic material. The molten metal is only handled once.
Small metal castings, such as those made by hobbyist, artist or professionals using, for example, five pounds or more of material, heretofore have been difficult or expensive to make. Further, extreme safety risks are created in the handling of the melted material, particularly when casting materials having high melting temperatures such as bronze. Bronze has a melting point of 2000.degree. fahrenheit.
Currently in order for hobbyist, artist or professionals to cast a metal object the object must be relatively small using small amounts of material and/or made of a material having a low melting point such as gold. Satisfying such constraints permits the use of small heaters such as those used by jewelers, small part makers, etc.
Small heaters used by jewelers satisfy the requirement of portability being that they can be moved and used in almost any setting and require standard household electricity to operate. However, such heaters suffer from various disadvantages. Namely the heaters can only melt small quantities of metallic material. Further, the heaters cannot be used to melt, for example, a pound or more of material used to cast works of art, machine parts or tools. In order for the hobbyist, artist or even a professional to cast small metal objects using approximately a pound or more of material larger furnaces, such as those owned by foundries, are used. Foundries typically use fuel fired furnaces. A fuel fired furnace 210 as illustrated in FIG. 2A has a cylindrical opening 212 for receiving a crucible 214 containing the material to be melted. The fuel fired furnace 210 also includes gas jets 216 that when lit applies a flame to the inside of the opening 212. The heat generated by the flame causes the metallic material contained in the crucible 214 to reach its melting point.
The above-described fuel fired furnace 210 suffers from various disadvantages. One disadvantage is that the fuel fired furnace 210 is not portable and can only be operated by professionals. Another most important disadvantage is that the melted material must be handled at least two times prior to casting.
Due to the construction of the fuel fired furnace 210 the crucible containing the metallic material must be vertically lowered into and lifted out of the opening 212 of the furnace by lifting tongs 218 as illustrated in FIG. 2B. The lifting tongs 218 are manipulated by two operators, one at either end of the lifting tongs 218. The two operators by manipulating the lifting tongs 218 causes the fingers 220 of the lifting tongs 218 to clamp about the crucible 214. The crucible 214 is then lifted out of the opening 212 of the furnace 210 in the vertical direction. Once the crucible 214 containing the melted material has been lifted out of the opening 212 of the furnace 210, the crucible 214 is then placed on the floor of the foundry within a pouring ring 222 of pouring tongs 224 as illustrated in FIGS. 2C and 2D. The pouring tongs 224 have a pouring finger 226 which clamps over the lip of the crucible 214 to prevent the crucible 214 from slipping out of the pouring ring 222 during pouring. Two operators are also necessary for manipulating the pouring tongs 224. One of the operators acts as a fulcrum while the other operator acts as the controller. The controller tilts the crucible 214 to control the pouring of the melted material by use of the handlebars 226.
Thus, the crucible containing the melted material is handled a first time when the crucible is lifted from the opening of the furnace and placed on the floor of the foundry using lifting tongs and a second time when the crucible is lifted from the floor of the foundry and the melted material is poured into the mold using the pouring tongs. Handling a melted material at temperatures sometimes as high as 2000.degree. fahrenheit can be extremely dangerous for the professional as well as the non-professional such as hobbyist and artist. Injury to the operator or damage to the surrounding area may occur.
Therefore, for professionals and particularly non-professionals there is a need to provide a furnace that is portable and easy to use and that reduces the number of times the melted material is handled.